Impact of organic pig production systems on CO2 emission, C sequestration and nitrate pollution

Organic rules for grazing and access to outdoor area in pig production may be met in different ways, which express compromises between considerations for animal welfare, feed self-reliance and negative environmental impact such as greeehouse gas emissions and nitrate pollution. This article compares environmental impact of the main organic pig systems in Denmark. Normally sows are kept in huts on grassland and finishing pigs are being raised in stables with access to an outdoor run. One alternative practised is rearing also the fattening pigs on grassland all year round. The third method investigated was a one-unit pen system mainly consisting of a deep litter area under a climate tent and with restricted access to a grazing area. Using life cycle assessment (LCA) methodology, the emissions of greenhouse gasses of the all free range system was estimated to be 3.3 kg CO2-equivalents kg-1 liveweight pig, which was significantly higher than the indoor fattening system and the tent system yeilding 2.9 and 2.8 kg CO2-eq. kg-1 pig respectively. This was 7-22% higher compared with Danish conventional pig production but, due to the integration of grass-clover in the organic crop rotations these had an estimated net soil carbon sequestration. When carbon sequestration was included in the LCA then the organic systems had lower green house gas emissions compared with the conventional pig production. Eutrophication in nitrate equivalents per kg pig was 21-65% higher in the organic pig systems and acidification was 35-45% higher per kg organic pig compared with the conventional system. We conclude that even though the all free range system theoretically has agro-ecological advantages over the indoor fattening system and the tent system due to a larger grass-clover area this potential is difficult to implement in practice due to problems with leaching on sandy soil. Only if forage can contribute a larger proportion of the pigfeed-uptake may the free range system be economically and environmentally competitive. Improvement of nitrogen cycling and efficiency is the most important factor for reducing the overall environmental load from organic pig meat. Presently a system with pig fattening in stables and concrete covered outdoor runs seems to be the best solution from an environmental point of view

The importance of economies of scale for reductions in greenhouse gas emissions from shipping

AbstractCO2 emissions from maritime transport represent 3.3% of the world's total CO2 emissions and are forecast to increase by 150%–250% by 2050, due to increased freight volumes (Second IMO GHG study, 2009). Fulfilling anticipated climate requirements (IPCC, 2007) could require the sector to reduce emissions per freight unit by a factor of five or six. The International Maritime Organization (IMO) is currently debating technical, operational and market-based measures for reducing greenhouse gas emissions from shipping. This paper also investigates the effects of economies of scale on the direct emissions and costs of maritime transport. We compared emissions from the current fleet (2007), with what can be achieved by increasing average vessel size. The comparison is based on the 2007 levels of trade and predictions for 2050. The results show that emissions can be reduced by up to 30% at a negative abatement cost per ton of CO2 by replacing the existing fleet with larger vessels. Replacing the whole fleet might take as long as 25 years, so the reduction in emissions will be achieved gradually as the current fleet is renewed

Seismic Imaging and Illumination with Internal Multiples

If singly scattered seismic waves illuminate the entirety of a subsurface structure of interest, standard methods can be applied to image it. It is generally the case, however, that with a combination of restricted acquisition geometry and imperfect velocity models, it is not possible to illuminate all structures with only singly scattered waves. We present an approach to use multiply scattered waves to illuminate structures not sensed by singly scattered waves. It can be viewed as a refinement of past work in which a method to predict artifacts in imaging with multiply scattered waves was developed. We propose an algorithm and carry out numerical experiments, representative of imaging of the bottom and flanks of salt, demonstrating the effectiveness of our approach.Dutch National Science Foundation (grant number NWO:VIVI865.03.007)StatoilHydroNorwegian Research Council (ROSE project)Geo-Mathematical Imaging Grou

Managing IT implementation in virtual enterprises

Konferansebidrag fra Engineering and Technology Management 1996 Vancouver. IEMC 1996The paper presents a framework of factors influencing information technology (IT) implementation in virtual enterprises. The framework is based on previous research on IT implementation, and field studies conducted in virtual enterprises. The aim is to increase the understanding of the implementation process in this organizational context, and the framework is intended as a basis for developing strategies for successful management of this proces